The boron carbonyl cation complexes B（CO）3＋, B（CO）4＋ and B2（CO）4＋ are studied by infrared photodissociation spectroscopy and theoretical calculations. The B（CO）4＋ ions are characterized to be very weakly b...The boron carbonyl cation complexes B（CO）3＋, B（CO）4＋ and B2（CO）4＋ are studied by infrared photodissociation spectroscopy and theoretical calculations. The B（CO）4＋ ions are characterized to be very weakly bound complexes involving a B（CO）3＋ core ion, which is predicted to have a planar D3h structure with the central boron retaining the most favorable 8-electron configuration. The B2（C0）4＋ cation is determined to have a planar D2h structure involving a B-B one and half bond. The analysis of the B-CO interactions with the EDA- NOCV method indicates that the OC→B cr donation is stronger than the B-＋CO π back donation in both ions.展开更多
Geometric model construction is the basis of infrared image theory simulation. Taking the construction of the geometric model of one building in Harbin as an example, this paper analyzes the theoretical groundings of ...Geometric model construction is the basis of infrared image theory simulation. Taking the construction of the geometric model of one building in Harbin as an example, this paper analyzes the theoretical groundings of simplification and principles of geometric model construction of buildings. It then discusses some particular treatment methods in calculating the radiation transfer coefficient in geometric model construction using the Monte Carlo Method.展开更多
Light illumination has been widely used to promote activity and selectivity of traditional thermal catalysts. Nevertheless, the role of light irradiation during catalytic reactions is not well understood. In this work...Light illumination has been widely used to promote activity and selectivity of traditional thermal catalysts. Nevertheless, the role of light irradiation during catalytic reactions is not well understood. In this work, Pt/Al2 O3 prepared by wet impregnation was used for photothermal CO2 hydrogenation, and it showed a photothermal effect. Hence, operando diffuse reflectance infrared Fourier-transform spectroscopy and density functional theory calculations were conducted on Pt/Al2 O3 to gain insights into the reaction mechanism. The results indicated that CO desorption from Pt sites including step sites(Ptstep) or/and terrace site(Ptterrace) is an important step during CO2 hydrogenation to free the active Pt sites. Notably, visible light illumination and temperature affected the CO desorption in different ways. The calculated adsorption energy of CO on Ptstep and Ptterrace sites was-1.24 and-1.43 e V, respectively. Hence, CO is more strongly bound to the Ptstep sites. During heating in the dark, CO preferentially desorbs from the Ptterrace site. However, the additional light irradiation facilitates transfer of CO from the Ptstep to Ptterrace sites and its subsequent desorption from the Ptterrace sites, thus promoting the CO2 hydrogenation.展开更多
The IR absorption, visible excited normal Raman, and UV-excited near-resonant Raman （UVRR） spectra of 1,1＇-binaphthyl-2,2＇-diamine （BINAM） were measured and analyzed. Density functional theory calculations were ...The IR absorption, visible excited normal Raman, and UV-excited near-resonant Raman （UVRR） spectra of 1,1＇-binaphthyl-2,2＇-diamine （BINAM） were measured and analyzed. Density functional theory calculations were carried out to investigate its vibrational frequencies, infrared absorption, normal Raman, and near-resonance Raman intensities. The observed Raman and IR bands of BINAM were assigned with respect to the local vibrations of substituted 2-naphthylamine. Several Raman bands of BINAM were found selectively enhanced in the UVRR in comparison with the normal Raman spectrum. Possible excited state geometry distortion was discussed based on the resonance Raman intensity analysis.展开更多
Geological structure and gas expansion when gas pressure was released can affect the distribution of infrared radiation energy or temperature at coal rock surface. From this, the foundation of roadway infrared surveyi...Geological structure and gas expansion when gas pressure was released can affect the distribution of infrared radiation energy or temperature at coal rock surface. From this, the foundation of roadway infrared surveying technical was formed. According to the thermodynamic principle of ideal gas and the law of energy conservation, the relation was established between gas gushing amount from coal rock and air temperature to fall in roadway. At the same time, this paper has analyzed coal rock density change that geological structure aroused and the change exerted influences on infrared radiation power at surface, as well as, has analyzed the infrared radiation feature of gas gushing at geological structure district. Application results show that infrared survey technology can be used to analyze and forecast the change of coal rock gas gushing effectively, and to guide the enforcement of the roadway gas project of prevention and handling economically.展开更多
Urea L-malic acid, a new second order nonlinear optical crystal, was studied using density functional theory （DFT）. PBEPBE/6-31＋G（d,p） method, the optimal method for comparing the results from the several DFT met...Urea L-malic acid, a new second order nonlinear optical crystal, was studied using density functional theory （DFT）. PBEPBE/6-31＋G（d,p） method, the optimal method for comparing the results from the several DFT methods, was chosen to study the molecular structure. Infrared and ultraviolet-visible spectra were obtained and compared with experiments. The ultraviolet-visible spectrum was also analyzed by the molecular orbital population. The geometries, and the infrared and ultraviolet-visible spectra in water were studied using DFT methods in combination with the polarized continuum model to predict the perturbations by the solvent effect.展开更多
Reaction of laser ablated zinc and cadmium atoms with SO2 molecules was studied by low temperature matrix isolation infrared spectroscopy. Cyclic M（SO2） and anion M（SO2）-（M=Zn, Cd） were produced in excess argon ...Reaction of laser ablated zinc and cadmium atoms with SO2 molecules was studied by low temperature matrix isolation infrared spectroscopy. Cyclic M（SO2） and anion M（SO2）-（M=Zn, Cd） were produced in excess argon and neon, which were identified by 34SO2 and S18O2 isotopic substitutions. The observed infrared spectra and molecular structures were confirmed by density functional theoretical calculations. Natural charge distributions indicated significant electron transfer from s orbitals of zinc or cadmium metal atom to S02 ligand and cyclic M（SO2） complexes favored ＂ion pair＂ M＋（SO2）-formation, which were trapped in low temperature matrices. In addition Zn-O or Cd-O bond in M（SO2） exhibited strong polarized covalent character. Reaction of Hg atom with SO2 was also investigated, but no reaction product was observed, due to the relativistic effect that resulted in the contraction of 6s valence shell and high ionization potential of Hg atom.展开更多
Among all CO2 electroreduction products,methane(CH4)and ethylene(C_(2)H_(4))are two typical and valuable hydrocarbon products which are formed in two different pathways:hydrogenation and dimerization reactions of the ...Among all CO2 electroreduction products,methane(CH4)and ethylene(C_(2)H_(4))are two typical and valuable hydrocarbon products which are formed in two different pathways:hydrogenation and dimerization reactions of the same CO intermediate.Theoretical studies show that the adsorption configurations of CO intermediate determine the reaction pathways towards CH4/C_(2)H_(4).However,it is challenging to experimentally control the CO adsorption configurations at the catalyst surface,and thus the hydrocarbon selectivity is still limited.Herein,we seek to synthesize two well-defined copper nanocatalysts with controllable surface structures.The two model catalysts exhibit a high hydrocarbon selectivity toward either CH4(83%)or C_(2)H_(4)(93%)under identical reduction conditions.Scanning transmission electron microscopy and X-ray absorption spectroscopy characterizations reveal the low-coordination Cu^(0)sites and local Cu^(0)/Cu^(+)sites of the two catalysts,respectively.CO-temperature programed desorption,in-situ attenuated total reflection Fourier transform infrared spectroscopy and density functional theory studies unveil that the bridge-adsorbed CO(CO_(B))on the low-coordination Cu^(0)sites is apt to be hydrogenated to CH4,whereas the bridge-adsorbed CO plus linear-adsorbed CO(CO_(B)+CO_(L))on the local Cu^(0)/Cu^(+)sites are apt to be coupled to C_(2)H_(4).Our findings pave a new way to design catalysts with controllable CO adsorption configurations for high hydrocarbon product selectivity.展开更多
基金The work was supported by the Ministry of Sci- ence and Technology of China （No.2013CB834603） and the National Natural Science Foundation of China （No.21173053 and No.21433005）.
文摘The boron carbonyl cation complexes B（CO）3＋, B（CO）4＋ and B2（CO）4＋ are studied by infrared photodissociation spectroscopy and theoretical calculations. The B（CO）4＋ ions are characterized to be very weakly bound complexes involving a B（CO）3＋ core ion, which is predicted to have a planar D3h structure with the central boron retaining the most favorable 8-electron configuration. The B2（C0）4＋ cation is determined to have a planar D2h structure involving a B-B one and half bond. The analysis of the B-CO interactions with the EDA- NOCV method indicates that the OC→B cr donation is stronger than the B-＋CO π back donation in both ions.
文摘Geometric model construction is the basis of infrared image theory simulation. Taking the construction of the geometric model of one building in Harbin as an example, this paper analyzes the theoretical groundings of simplification and principles of geometric model construction of buildings. It then discusses some particular treatment methods in calculating the radiation transfer coefficient in geometric model construction using the Monte Carlo Method.
基金supported by the National Natural Science Foundation of China(U1862111,U1232119)Sichuan Provincial International Cooperation Project(2017HH0030)the Innovative Research Team of Sichuan Province(2016TD0011)~~
文摘Light illumination has been widely used to promote activity and selectivity of traditional thermal catalysts. Nevertheless, the role of light irradiation during catalytic reactions is not well understood. In this work, Pt/Al2 O3 prepared by wet impregnation was used for photothermal CO2 hydrogenation, and it showed a photothermal effect. Hence, operando diffuse reflectance infrared Fourier-transform spectroscopy and density functional theory calculations were conducted on Pt/Al2 O3 to gain insights into the reaction mechanism. The results indicated that CO desorption from Pt sites including step sites(Ptstep) or/and terrace site(Ptterrace) is an important step during CO2 hydrogenation to free the active Pt sites. Notably, visible light illumination and temperature affected the CO desorption in different ways. The calculated adsorption energy of CO on Ptstep and Ptterrace sites was-1.24 and-1.43 e V, respectively. Hence, CO is more strongly bound to the Ptstep sites. During heating in the dark, CO preferentially desorbs from the Ptterrace site. However, the additional light irradiation facilitates transfer of CO from the Ptstep to Ptterrace sites and its subsequent desorption from the Ptterrace sites, thus promoting the CO2 hydrogenation.
基金This work was supported by the National Natural Science Foundation of China （No.21273211, No.21573208）, USTC-NSRL Association Foundation （No.NSRLLHJJ（14-15-012）, and the Supercomputation Center of USTC.
文摘The IR absorption, visible excited normal Raman, and UV-excited near-resonant Raman （UVRR） spectra of 1,1＇-binaphthyl-2,2＇-diamine （BINAM） were measured and analyzed. Density functional theory calculations were carried out to investigate its vibrational frequencies, infrared absorption, normal Raman, and near-resonance Raman intensities. The observed Raman and IR bands of BINAM were assigned with respect to the local vibrations of substituted 2-naphthylamine. Several Raman bands of BINAM were found selectively enhanced in the UVRR in comparison with the normal Raman spectrum. Possible excited state geometry distortion was discussed based on the resonance Raman intensity analysis.
文摘Geological structure and gas expansion when gas pressure was released can affect the distribution of infrared radiation energy or temperature at coal rock surface. From this, the foundation of roadway infrared surveying technical was formed. According to the thermodynamic principle of ideal gas and the law of energy conservation, the relation was established between gas gushing amount from coal rock and air temperature to fall in roadway. At the same time, this paper has analyzed coal rock density change that geological structure aroused and the change exerted influences on infrared radiation power at surface, as well as, has analyzed the infrared radiation feature of gas gushing at geological structure district. Application results show that infrared survey technology can be used to analyze and forecast the change of coal rock gas gushing effectively, and to guide the enforcement of the roadway gas project of prevention and handling economically.
基金ACKNOWLEDGMENTS This work was supported by the Program for New Century Excellent Talents in University, the Science and Technology Foundation for Young Scholars in Sichuan Province, and the National Natural Science Foundation of China （No.10774104）.
文摘Urea L-malic acid, a new second order nonlinear optical crystal, was studied using density functional theory （DFT）. PBEPBE/6-31＋G（d,p） method, the optimal method for comparing the results from the several DFT methods, was chosen to study the molecular structure. Infrared and ultraviolet-visible spectra were obtained and compared with experiments. The ultraviolet-visible spectrum was also analyzed by the molecular orbital population. The geometries, and the infrared and ultraviolet-visible spectra in water were studied using DFT methods in combination with the polarized continuum model to predict the perturbations by the solvent effect.
文摘Reaction of laser ablated zinc and cadmium atoms with SO2 molecules was studied by low temperature matrix isolation infrared spectroscopy. Cyclic M（SO2） and anion M（SO2）-（M=Zn, Cd） were produced in excess argon and neon, which were identified by 34SO2 and S18O2 isotopic substitutions. The observed infrared spectra and molecular structures were confirmed by density functional theoretical calculations. Natural charge distributions indicated significant electron transfer from s orbitals of zinc or cadmium metal atom to S02 ligand and cyclic M（SO2） complexes favored ＂ion pair＂ M＋（SO2）-formation, which were trapped in low temperature matrices. In addition Zn-O or Cd-O bond in M（SO2） exhibited strong polarized covalent character. Reaction of Hg atom with SO2 was also investigated, but no reaction product was observed, due to the relativistic effect that resulted in the contraction of 6s valence shell and high ionization potential of Hg atom.
基金supported by the National Natural Science Foundation of China (21875042)Shanghai Science and Technology Committee (18QA1400800)+1 种基金the Program of Eastern Scholar at Shanghai Institutions and Yanchang Petroleum Groupsupported by the Frontier Research Center for Materials Structure, School of Materials Science and Engineering of Shanghai Jiao Tong University
文摘Among all CO2 electroreduction products,methane(CH4)and ethylene(C_(2)H_(4))are two typical and valuable hydrocarbon products which are formed in two different pathways:hydrogenation and dimerization reactions of the same CO intermediate.Theoretical studies show that the adsorption configurations of CO intermediate determine the reaction pathways towards CH4/C_(2)H_(4).However,it is challenging to experimentally control the CO adsorption configurations at the catalyst surface,and thus the hydrocarbon selectivity is still limited.Herein,we seek to synthesize two well-defined copper nanocatalysts with controllable surface structures.The two model catalysts exhibit a high hydrocarbon selectivity toward either CH4(83%)or C_(2)H_(4)(93%)under identical reduction conditions.Scanning transmission electron microscopy and X-ray absorption spectroscopy characterizations reveal the low-coordination Cu^(0)sites and local Cu^(0)/Cu^(+)sites of the two catalysts,respectively.CO-temperature programed desorption,in-situ attenuated total reflection Fourier transform infrared spectroscopy and density functional theory studies unveil that the bridge-adsorbed CO(CO_(B))on the low-coordination Cu^(0)sites is apt to be hydrogenated to CH4,whereas the bridge-adsorbed CO plus linear-adsorbed CO(CO_(B)+CO_(L))on the local Cu^(0)/Cu^(+)sites are apt to be coupled to C_(2)H_(4).Our findings pave a new way to design catalysts with controllable CO adsorption configurations for high hydrocarbon product selectivity.
